Heretofore known is the technology (dissolved resin suspending method) for preparing resin particles which comprises dissolving a resin in a solvent in advance, dispersing the resin solution in an aqueous medium in the presence of a surfactant or a dispersant (auxiliary dispersant), such as a water-soluble polymer, and removing the solvent by heating or pressure reduction (examined Japanese Patent Publication No. 28688/1986, unexamined Japanese Patent Publication No. 25664/1988, etc.), but this technology has the disadvantage that the product particles are inadequate in the uniformity of particle diameter and require a classification procedure in order that the proper diameter uniformity may be attained.
In connection with this dissolved resin suspending method, a process comprising the use of a finely divided inorganic powder, such as calcium carbonate, silica, or the like, as a dispersion stabilizer to give resin particles of uniform diameter is also known (unexamined Japanese Patent Publication No. 319144/1997, etc.).
However, the resin particles obtained by the above technologies have finely divided inorganic powders adhered. The finely divided inorganic powders are hardly removable and even if a step for their removal is interposed, the inorganic particles remaining in trace amounts adversely affect the electrical and thermal properties and chemical stability of the resin particles.